Rotatable yarn guides adapted for use on double twist spindles



w. LENK 3,133,403 ROTATABLE YARN GUIDES ADAPTED FOR USE ON DOUBLE TWIST SPINDLES May 19, 1964 Filed Feb. 8, 1963 WALTER LENK ATT 'YS United States Patent 3,133,403 RUTATABLE YARN SUTDES ADAhTED FGR USE 0N DUUBLE TWKST SPTNDLES Walter Leah, Remscheid-Lennep, Germany, assignor to Barmer Maschinenfahrilr Airtiengeseilschait, WrappertahQherb-armen, Germany Filed Feb. 3, 19%, Ser. No. 257,249 Qlaims priority, application Germany Feb. 16, 1962 8 Qiaims. (til. 57--53.36)

This invention, in general, relates to rotatable yarn guides coupled with means for varying the rate of rotation of the yarn guides in reponse to change in yarn tension. Furthermore, the invention relates to rotatable yarn guides of the aforesaid character in combination with a double twist spindle.

Rotatable yarn guides, i.e., arms or wings, are known in the prior art. These yarn guides have a yarn-conducting eye or ring positioned radially beyond the ClICHii: ference of a yarn winding of a fixed or freely rotatable spool mounted on the double twist spindle. These yarnconducting guides rotate at a rate dependent upon the drawing oil speed of the yarn from the spool and also dependent on the circumference of the winding on the spool. They are used to aid in drawing off the yarn from the spool and, through an angular deflection in the yarn path as it passes through the guide member, act as a regulating brake for the yarn for balancing of yarn tension fluctuations. The angular deflection results from lag in the rotation of the yarn guide with respect to the point at which the yarn is being lifted oil the yarn winding on the spool.

The use of yarn spools of relatively large winding diameter often results, in the prior art devices, particularly where there is a great difference between the fully wound diameter of the winding and the diameter of the innermost windings, in difficulties producing an undesirable eiiect on the twisting process or on the twisted yarn. These difficulties are due primarily to the fact that the tension of the yarn drawn off from the feed spool at constant velocity drives the rotatable guide yarn at rates of rotation increasing with diminishing winding diameter of the winding on the spool. The deflection angle of the yarn course as it passes through the guide member on the rotatable arm becomes smaller and smaller. Furthermore, the drag friction on the yarn at the point of deflection in the guide member rises with diminishing diameter of the spool winding. This rise in the yarn tension results in gradual consumption of the yarn reserve in the yarn reservoir part of the twist spindle until the yarn balloon produced by the yarn exiting from the double twist spindle ultimately collapses, whereupon the yarn breaks.

The primary objective of this invention is to provide rotatable yarn guides useable on double twist spindles having structural means for decreasing the drag force resisting rotation of the rotatable guide arm or Wing when the yarn tension increases. This may be accomplished, in accordance with the invention, by shifting the orbital path of the yarn guide in response to change in tension of the yarn being drawn through the orbiting guide member. The shift in orbital path of the yarn guide member causes a responsive change in the rotational drag force resisting the rotation of the rotatable arm or wing carrying the guide member. The change in the orbital path of the yarn guide member may be a radially inward change in response to increasing yarn tension, or, in a more preferred form, it may be an arcuate movement of the orbiting guide member in an are at right angles to the plane of orbit of the yarn guide member. The latter is preferably accomplished by mounting the wing or arm of the yarn guide member on the rotatable head for pivotal movement of the wing or arm about an axis substantially intersecting but at right angles to the axis of rotation of the head.

Broadly speaking, the rotatable yarn guides of the invention operate in a manner similar to the known rotatable drag guides used on double twist spindles. Rotated by the yarn running through the yarn guide, the arm or wing turns about the double twist spindle axis. In the invention, a rotatable head supporting the arm or wing slides on a drag surface concentric with the spindle axis. As a consequence of the lag in the rotational position of the yarn guide member of the arm or wing with respect to the position on which the yarn being drawn off the spool on the double twist spindle, the yarn guide member functions as a thread brake. The adverse effects of increasing yarn tension accompanying decrease in the winding diameter on the spool is compensated by the shifting of the orbital path of the yarn guide member and its arm or wing to another path of orbit in which the drag friction between the rotatable head and drag surface is responsively caused to be less. As a consequence of the reduction or elimination of the drag effect on the rotatable head of the arm or wing, it can now rotate at a more rapid rate and draw of? the required amount of yarn from the feed spool, whereupon the yarn tension again reaches normal. The yarn guide and its arm or wing now resume their normal orbital path.

When the yarn tension drops back to normal, drag force on the rotatable head returns to its normal drag value until such time as the yarn tension, having increased again, forces the arm or wing into another position wherein the drag force on the arm or wing rotatable head again decreases. This alternation is repeated again and again in the double twisting operation.

It is further possible in accordance with the invention, to decrease or increase the drag on the rotatable head in two or more stages in which the magnitude of the frictional torque on the wing or arm spindle diminishes with increasing degree of movement of the arm or wing and its yarn guide member from its normal orbital path. Preferably, this is accomplished in a manner whereby two or more means operate in successive stages for progressively decreasing the drag friction between the rotatable head and its bearing surface, each of said means coming into operation successively as the change in orbital path of the arm or wing and its yarn guide becomes greater.

it is thus possible, by the practice of this invention, to provide double twist spindles which respond quickly to changes and fluctuations in tie yarn feed tension and automatically balance, to a great extent, the changes or fluctuations in the yarn feed tension so that the latter has a uniformity sutliciently constant to eliminate the adverse eifects heretofore noted with respect to the prior art devices, especially in the case of yarn feed to double 7 E5 twisting spindles from feed spools of initial, relatively large diameter.

The principles of structure and operation of the rotatable yarn guides heretofore described may be put into practical form by many embodiments, some of which are illustrated in the accompanying drawing wherein:

FIG. 1 is a side elevation in fragment of the :upper portion of a double twist spindle;

FIG. 2 is a cross-sectional view taken on section line 2-2 of FIG. 1;

FIG. 3 is a fragmentary cross-sectional view taken on a diametric plane through the rotatable head for the rotatable arms or wings of the embodiment and shows the arms or wings in normal crating position;

FIG. 4 is a cross-sectional view similar to a view of FIG. 3 with the arms or wings in a tilted angle resulting from an increase in tension of the yarn drawn through the guide member;

P16. is a fragmentary, cross-sectional view similar to FIG. 3 but showing another embodiment of the invention; and

FIG. 6 is a fragmentary, cross-sectional view taken on the same plane as are the views of FIGS. 3-5 and showing a still further embodiment of the invention.

The double twist spindle 1 is shown only in fragment. The lower end of the double twist spindle may be of any conventional structure providing a yarn accumulating member, e.g., similar to the spindle structure shown in US. Patent Nos. 2,867,963, 2,939,268, or 3,018,604. The double twist spindle 1 has a yarn feed spool 2 fixedly mounted or freely rotatably mounted about the axis of the double twist spindle. The spool 2 carries a wound body 3 of yarn thereon which serves as the yarn feed to the double twisting spindle.

The yarn 4 is drawn from the winding body 3 through a guide eye or loop 5 mounted in the sloping, U-shaped portion 6 formed by the wires or rods 7 of the rotatable arm or wing 8. A similar guide eye or loop 9 mounted in the U shaped, sloping portion 111 or" the radially extending rods or wires 11 of a diametrically opposite arm 12 may also be employed in the rotatable arm or wing structure of the device. The arms or wings 8 and 12 are of preferably substantially identical construction so that one counterbalances the other when the arms or wings rotate.

The rods or wires 7, 11 are joined at their inner ends by arcuate segments 13, 14 in the rods or wires. The rod or wire structure of the arms 8 and 12 and the arcuate segments 13, 14 may be made from a single wire or rod bent substantially as shown in FIGS. 1 and 2.

The arcuate segments 13, 1 i carry at substantially their mid-point radially inwardly directed pins 15 which are rotatably journalled in holes in the cylindrical wall of the arm-or-wing-supporting, rotatable head 16. The head 16 and the arms or wings carried thereby are rotatable about the axis of the double twist spindle while the arms or wings 8, 12 are pivotable about the axis of the pins 15 in a direction transverse to the axis of rotation of the head 16. The head 16 and its arms or wings are rotated by the yarn running through either guide eye 5 or 9. The axis of rotation of the pins 15 intersects or substantially intersects the axis of rotation of the head 16.

The head 16 is a hollow sleeve which has at its lower end a flange 17. The lower surface of the flange 17 has mounted thereon a brake-liner ring 18 which normally rides on another brake-liner ring 19. The latter ring is fixedly attached to the upper surface of the flange 21 of the fixed hub or collar 24) of the double twist spindle. The spool 2 is rotatably or fixedly mounted on the hub or collar 20.

The head 16, its flange 17 and the brake-liner ring 18 rotate relative to the hub or collar 29 and its brake-liner 19. The brake-liner rings 18, 19, in the normal operating position, are in contact and exert a drag force on the rotation of the head 16. This drag force, in the normal operation, depends on the weight of the head 16 and its associated parts. The amount of drag exerted can be increased by increasing the weight of the head 16 and its associated parts and can be adjusted, for example, by providing on the head 16 a flange 22 on which rest one or more ring weights 23. The amount of normal drag, therefore, can be increased or decreased by adding or removing ring weights 23.

The double twist spindle has the usual yarn guide tube 24 (shown in fragment in FIGS. 36) extending longitudinally' through the double twist spindle. The yarn guide tube 24 conducts the running yarn longitudinally through the double twist spindle from its point of entry at the yarn brake 26 of conventional construction to its point of exit in the yarn reservoir or accumulator at the lower end of the double twist spindle (not shown).

The rotatable head 16 is rotatably journalled on the yarn guide tube 24 by the bearing 25 and is movable upwardly and downwardly relatit e to the tube 24. The head 16 has for its axis of rotation the axis of the yarn guide tube 24, which, in turn, is positioned concentrically in the double twist spindle. The arms or wings 8, 12, in turn, can pivot through a small angle about the axis of the pins 15. The latter pivotal movement, in turn, results from fluctuation or change in tension of the yarn 4 passing through and deflected over the guide ring 5. This pivotal movement of the arm 8 by fluctuations or changes in yarn tension is used to increase or decrease the drag force exerted by the brake-liner rings 18, 19 in the following manner.

Each of the arms 8, 12 have upper and lower clamp plates 27, 2S clamped on the wires or rods 7, 11 by screws 29. The clamp plates 27, 28 also have clamped therebetween shanks 311, 3'1 directed radially inwardly toward the axis of rotation of the head 16. The shanks 30, 31 carry radially inwardly directed stub axles 32, 33, each of which has rotatably mounted on its radially inner end a wheel 34, 35. The stub axles 32, 33 extend through apertures 37, 38 in the cylindrical wall of the head 16. When the arms 8, 12 are in their normal, level position, the wheels 34, 35 are both slightly above the upper hearing surface 36 of the collar or hub 20. When an increase in yarn tension causes the arms 8, 12 to tilt from the normal position, e.g., the tilted position shown in FIG. 4, the wheel 35 pivots about the axis formed by the pins 15. When the wheel 35 contacts the bearing surface 36, the rotatable head 16 is raised slightly by virtue of the pin connections provided by pins 15. The raising of the head 16 by even a very slight amount decreases the drag force between the brake-liner rings 18, 19, allowing the head 16 and the arms 3, 12 mounted thereon to rotate or orbit at a faster velocity under the influence of increased tension in the yarn 4 until the yarn guide eye 5 is restored into its normal lag position in the orbital path of the latter. When the yarn tension returns to normal, the arms 8, 12 assume their normal position wherein the wheel 35 only lightly touches or is raised 011 the bearing surface 36, allowing the drag force to again return to its normal value.

The function, therefore, of the tiltable arms 8, 12 is to counteract the drag force exerted by the weight of the upwardly and downwardly movable head 16 by either diminishing the pressure of brake-liner ring 18 on brakeliner ring 19 or totally eliminating the drag force between the brake-liners if the head 16 is raised sufiiciently to eliminate contact between the liners. The change in drag force, therefore, is dependent upon the degree to which the arm 8 is pendulated about the axis of the pins 15, the latter degree, in turn, being a function of the extent of change in yarn tension of the yarn passing through the guide eye or ring 5. The rate of rotation of the arms 8, 12 and head 16, accordingly, is quickly responsive to minor or major fluctuations in yarn tension, the magnitude of change in rate of rotation of the arms 8, '12 and the head 16, in tum, being proportional to the amount of increase in yarn tension.

The embodiment of FIG. 5 is similar in structure and in operation to the embodiment of FIGS. 1-4, the primary difference being that the stub axles 32, 33 and wheels 34, 35 of the embodiment of FIGS. 1-4 are replaced by pins 39 having downwardly directed tips which slidably contact the bearing surface 36 when the arms 8, 12 til-t to a position similar to the position of FIG. 4. The pivoting of the arms or wings 8, 12 after contact of the tips of pins 39 on the bearing surface 36 causes the head 16 to be raised slightly in the same manner as described for the previous embodiment.

The embodiment of FIG. 6 provides a multistage or stepped decrease in the frictional drag force between brake-liner rings 18, 19. In this embodiment, the stub axles 32, 33 have a tipped end 42 which contacts first the bearing surface 36 of the hub or collar 21. The tip 42 is positioned relative to the bearing surface 36 so that it causes the head 16 to raise very slightly to decrease the pressure of brake-liner ring 18 on brake-liner ring 19 without loss of total contact between the brakeliner rings or to eliminate the pressure. When the arms 3, 12 tilt even further, the wheel '41, rotatably mounted 'on the stub axle 33, contacts the annular bearing surface 40 of the flange 21 of the hub or collar 20 and further raises the head 16 upwardly to a point where the brakeliner rings 18, 19 or the tip 42 with the bearing surface 36 are no longer in contact. This gives a step-wise or multistage operation in the increasing or decreasing of the angular velocity of the arms 8, 12 responsive to fluctuations in the yarn tension.

Besides compensating for fluctuations in yarn tension, the invention also compensates for the progressive increase in tension of the drawn off yarn :as its winding diameter on the feed spool decreases upon exhaustion of the spool.

The unavoidable gradual increase in yarn tension upon exhaustion of the feed spool is compensated by decreasing the rotational drag force in the manner heretofore described in a cyclic fashion. The movement of the arms or wings out of and back to their normal orbital path may be so slight that they are imperceptible or barely perceptible to the eye. This is because the drag force increasing or decreasing mechanism is quickly responsive to increases or decreases n yarn tension.

The basic principles of the invention can be readily employed for drawing yarn from feed spools with large winding diameter and large difference between outside and inside diameter of the winding for twisting on doubletwist spindles, especially for the production of twists wherein the yarns are drawn off from the plying spool at a high speed and which receive only a slight twist. Whereas heretofore, because of the progressively large increase in tension in the fed yarn, it was necessary to maintain a certain narrow ratio of outside to inside diameter of the yarn winding of the feed spool and also several yarn windings as regulating reserve in the yarn reservoir or accumulator. Even then, this yarn reserve was nevertheless gradually used up during the twisting process. Often, before completion of the same, the yarns had a tendency to climb over each other in the windings or otherwise, especially in the case of cotton or fibrous carpeting yarns, to cause trouble because of their slipping properties. It is now possible, by employment of the principles of this invention, without difliculty, to use yarn feed spools with great difference between outside and inside diameter of the winding, and there is needed only a yarn encircling of less than 360 as regulating reserve on the reservoir or accumulator. Surprisingly, it has been ascertained that this yarn reserve remains preserved in its size until the exhaustion of the yarn on the feed spool.

The structure of the double-twist spindle by which the yarn is ballooned and twisted, and the yarn accumulator or reservoir ring or groove associated therewith, do not constitute an essential part of the invention. Any suitable structure, such as is illustrated in the above enumerated patents, may be employed in putting this invention to practice on double-twist spindles.

The invention is hereby claimed as follows:

1. The combination comprising a rotatable head, an arm extending outwardly from said head, a yarn guide carried by said arm, drag means exerting a rotational drag force on said rotatable head, means mounting said arm on said head for rotation with said head and also for limited movement of said arm relative to said head upon an increase in tension of yarn running through said yarn guide when said head and arm are rotating, and means operatively associated with said arm and responsive to said movement of said arm upon said increase in tension of said yarn for decreasing said rotational drag force on said head.

2. The combination comprising a rotatable head, an arm extending outwardly from said head, means mounting said arm on said head for pivotal movement of said arm relative to said head about an axis of rotation transverse to the axis of rotation of said head, a yarn guide carried by said arm, drag means exerting a rotational drag force on said head, and means responsive to pivotal movement of said arm relative to said head resulting from an increase in tension of yarn running in a deflected path over said yarn guide when said head and arm are rotating for decreasing said rotational drag force on said head.

3. A double twist mechanism comprising a double twist device with a yarn guide passage extending axially through said double twist device, a wound yarn spool on said device, a rotatable head on said device rotatable about said passage, an arm mounted on and extending outwardly from said head, a yarn guide carried by said arm through which yarn from said spool passes when it is drawn through said passage, said arm and head being rotated by the passage of the yarn from said spool into said passage through said yarn guide, drag means on said twist device exerting a rotational drag force on said head, and means responsive to an increase in tension of yarn running through said yarn guide, when said head and arm are rotated by said yarn passing through said yarn guide, for decreasing said rotational drag force on said head.

4. A double twist mechanism comprising a double twist device with a yarn guide passage extending axially through said double twist device, a wound yarn spool on said device, a rotatable head on said device rotatable about said passage, an arm mounted on and extending outwardly from said head, said arm being mounted on said head by means providing for pivotal movement of said arm relative to said head about an axis of rotation transverse to the axis of rotation of said head, a yarn guide carried by said arm through which yarn from said spool passes when it is drawn through said passage, said arm and head being rotated by the passage of the yarn from said s ool into said passage through said yarn guide, drag means on said twist device exerting a rotational drag force on said head, and means responsive to pivotal movement of said arm relative to said head resulting from an increase in tension of yarn running in a deflected path over said yarn guide when said head and arm are rotating for decreasing said rotational drag force on said head.

5. The combination comprising a member having a fixed ring-shaped braking surface on the upper side thereof, a rotatable head having on its lower side a ring-shaped braking surface bearing on said first mentioned braking surface, the friction between said braking surfaces providing a rotational drag force opposing rotation of said head relative to said member, an arm extending outwardly from said rotatable head, a yarn guide on said arm, said arm being mounted on said head by means "'7 a providing for movement of said arm relative to said head, and means carried by said arm to decrease the bearing force of said head on said member upon movement of said arm relative to said head caused by an increase in tension of yarn running through said yarn guide on said arm.

6. The combination as claimed in claim 5, wherein said means is operable in stages of progressively decreasing bearing force of said head on said member.

7. The combination comprising a member having a fixed ring-shaped braking surface on the upper side there of, a rotatable head having on its lower side a ring-shaped braking surface bearing on said first mentioned braking surface, the friction between said braking surfaces providing a rotational drag force opposing rotation of said head relative to said member, an arm extending outwardly from said rotatable head, a yarn guide on said arm, said arm being pivotally mounted on said rotatable head,

25 and a member carried by said arm at the radially inner portion thereof adapted to contact said member and raise said head as said head and arm rotate when said arm is pivoted relative to said head under an increase in tension of yarn running through said yarn guide.

8. The combination as claimed in claim 7, wherein said member carried by said arm is a Wheel adapted to bear against said member when said arm is pivoted under said increase in tension of said yarn.

References Cited in the file of this patent UNITED STATES PATENTS 1,884,684 Herr Oct. 25, 1932 2,015,558 Herr Sept. 24, 1935 2,093,135 McHale Sept. 14, 1937 2,524,217 Acnet Oct. 3, 1950 2,762,583 Lenk Sept. 11, 1956 

1. THE COMBINATION COMPRISING A ROTATABL, HEAD, AN ARM EXTENDING OUTWARDLY FROM SAID HEAD, A YARN GUIDE CARRIED BY SAID ARM, DRAG MEANS EXERTING A ROTATIONAL DRAG FORCE ON SAID ROTATBLE HEAD, MEANS MOUNTING SAID ARM ON SAID FOR ROTATION WITH SAID HEAND AND ALSO FOR LIMITED MOVEMENT OF SAID ARM RELATIVE TO SAID HEAD UPON AN INCREASE IN TENSION OF YARN RUNNING THROUGH SAID YARN GUIDE WHEN SAID HEAD AND ARM ARE ROTATING, AND MEANS OPERATIVELY ASSOCIATED WITH SAID ARM AND RESPONSIVE TO SAID MOVEMENT OF SAID ARM UPON SAID INCREASE IN TENSION OF SAID YARN FOR DECREASING SAID ROTATIONAL DRAG FORCE ON SAID HEAD. 